type t = [
  | #"switch"
  | #alert
  | #alertdialog
  | #application
  | #article
  | #banner
  | #button
  | #cell
  | #checkbox
  | #columnheader
  | #combobox
  | #complementary
  | #contentinfo
  | #definition
  | #dialog
  | #directory
  | #document
  | #drawerlayout
  | #dropdownlist
  | #feed
  | #figure
  | #form
  | #grid
  | #group
  | #heading
  | #horizontalscrollview
  | #iconmenu
  | #img
  | #link
  | #list
  | #listitem
  | #log
  | #main
  | #marquee
  | #math
  | #menu
  | #menubar
  | #menuitem
  | #meter
  | #navigation
  | #none
  | #note
  | #option
  | #pager
  | #presentation
  | #progressbar
  | #radio
  | #radiogroup
  | #region
  | #row
  | #rowgroup
  | #rowheader
  | #scrollbar
  | #scrollview
  | #searchbox
  | #separator
  | #slider
  | #slidingdrawer
  | #spinbutton
  | #status
  | #summary
  | #tab
  | #table
  | #tablist
  | #tabpanel
  | #term
  | #timer
  | #toolbar
  | #tooltip
  | #tree
  | #treegrid
  | #treeitem
  | #viewgroup
  | #webview
]
